Electron beam exciter for use in chemical analysis in processing systems

Abstract

The present invention is directed to a gas line electron beam exciter, gas line electron beam excitation system and method for exciting a gas using an electron beam exciter. The electron beam exciter generally comprises a variable density electron source for generating a cloud of electrons in an electron chamber and a variable energy electron extractor for accelerating electrons from the electron chamber as an electron beam and into an effluent stream for fluorescing species in the effluent. The electron density of the electron beam is variably controlled by adjusting the excitation power applied to the variable density electron source. The electrons in the electron chamber reside at a reference electrical potential of the chamber, typically near ground electrical potential. The electron energy of the electron beam is variably controlled by adjusting an electrical potential across the variable energy electron extractor, which energizes the electrons through an extraction hole of the chamber and toward the extractor. The greater the difference in the electrical potential between the electron extractor and the electron source, the higher the energy imparted to the electrons in the electron beam. The excitation power applied to the electron source can be adjusted independently from the electron energy of the electron beam, thereby altering the electron density of the electron beam without changing the energy level of the electrons of the electron beam.